


The Switch Up

by fuzipenguin



Series: Well Kept [5]
Category: Transformers Generation One
Genre: BDSM, Biting, Bloodplay, Bondage, Bukkake, Collars, Dom/sub, Established Relationship, M/M, Mildly Dubious Consent, Other, Painplay, Roleplay, Sensation Play, Spanking, Twincest
Language: English
Status: Completed
Published: 2015-11-01
Updated: 2015-11-01
Packaged: 2018-04-29 08:55:35
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,962
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5122379
Author URL: https://archiveofourown.org/users/fuzipenguin/pseuds/fuzipenguin
Summary: <blockquote class="userstuff">
              <p>In a response to Sunstreaker wanting a little more pain in their sessions, Sideswipe takes it upon himself to be the guinea pig. And maybe get a little something out of it as well...</p>
            </blockquote>





	The Switch Up

**Author's Note:**

> Takes place a little after New Methods and Aftershocks, way before Jazz and Optimus

                “No! Stop! That’s too hard! Why are you doing this?!” Sideswipe cried, his arms twisting above his head as he strained against his bonds.

                If Sunstreaker hadn’t been sunk deep into their link, his twin encouraging him with both words and nonverbal pulses of emotion, he might have believed Sideswipe’s act. It was frighteningly realistic. His energy field was rippling with distress, his protests pitched with just the right amount of panic and fear. He was even squirming and wriggling credibly.

                Sideswipe was on his knees, arms pulled forward and nearly vertically above his head. His wrists were cuffed together, the links between them hooked onto a chain attached to one of the main support beams in the ceiling. His legs were also bound, a spreader bar between his ankles and knees slid backwards instead of squarely in line with his hips.

                If it had been Sunstreaker bound this way, Sideswipe would probably have said that he was ‘optimally arched’ or some such slag. He specifically researched things like this, trying to find positions which would stretch physical limitations over time.

                By now, Sideswipe’s limitations were definitely being put to the test. Neither his legs nor his arms were pulled taut enough to give him complete support and if he wasn’t concentrating on keeping his abdominal cables taut, his pelvis would start to sink downwards as if there were a weight attached to it. Every time he did, Sunstreaker’s thrusts from behind became much shallower, which was usually enough incentive for him to straighten up. If not, a heavy blow to his aft also did it too.

                Sideswipe also had a collar fastened around his throat. A thin chain was attached to the D-ring at the back of the thick metal band, the chain stretching upwards to another hook in the ceiling, keeping his helm tugged backwards just slightly.

                They had tried this particular collar on Sunstreaker once, but it hadn’t lasted long. It was a cruel little thing, although the pain that the sharp pikes lining the collar had caused hadn’t been the reason it had come off so quickly. Apparently compression of his neck and throat panicked him. Or at least that’s what Sideswipe had told him; Sunstreaker honestly didn’t remember, but that was probably telling enough.

                As it was, Sideswipe kept straining against the collar, and little rivulets of energon continually trailed down his shoulders and chest. Sunstreaker was pretty sure he was doing it on purpose, especially since Sideswipe kept reminding him that Sunstreaker had free reign to damage him. Bite him, dent him, smack him… any kind of superficial injury was permissible. And greatly welcomed.

                _That’s it, Sunny. You’re doing great_ , Sideswipe crooned encouragingly when Sunstreaker yanked Sideswipe’s hips back into the next thrust.

                Sunstreaker didn’t know how his brother did it. Sideswipe was flawlessly managing the unwilling victim act while fully enjoying everything being done to him. _And_ directing every one of Sunstreaker’s actions and words. He was both subbing and topping, and Sunstreaker could barely comprehend it.

                _You doing ok?_

                _I’m good,_ Sunstreaker replied, fingers slipping in the condensation which drenched Sideswipe’s lower back. He had overloaded twice already, the first from sheer excitement when Sunstreaker had originally penetrated him. Sunstreaker, on the other hand, was wearing a spike ring. He wouldn’t reach completion until Sideswipe told him to.

                _You about ready for that lube?_ Sideswipe inquired excitedly. His eagerness was showing; he was struggling less, and his pelvis was subtly canted to better meet each plunge of Sunstreaker’s spike.

                In answer, Sunstreaker drew back, releasing his brother with a dismissive little shove. Sideswipe sagged in his chains, whimpering. A hard swat to the aft made Sideswipe yelp and twist his hips away.

                “Please… please no more…” Sideswipe cried softly, trying to bury his face against one of his arms.

                “I’ll do with you what I like. You’re my frag toy, aren’t you?” Sunstreaker snapped, landing another firm blow against Sideswipe’s upper right thigh. Their bond practically swelled with satisfaction on Sideswipe’s end.

                “Yes, sir, yes I am, I know I am, but I’m just so sore…” Sideswipe whimpered, straining against the spreader bar in a futile attempt to close his legs.

                “Well, isn’t that just too bad,” Sunstreaker commented snidely, abruptly plunging four fingers deep inside Sideswipe’s port. Lubricant welled up around Sunstreaker’s digits, overflowing to drip into the growing puddle between their knees.

                Sideswipe wailed, throwing his head back, the chains attached to his wrists rattling mightily. Thank Primus their room was at the end of the hall, and they didn’t have neighbors. Although by now the whole crew knew how vocal Sideswipe could get in the midst of interfacing.

                _Nnnggh… that’s good, Sunny_ , Sideswipe’s slurred voice said. _Keep talking to me like that_.

                “You’re here for me to use you, that’s all. And if I want to shove my whole fist inside you…” Sunstreaker trailed off, suggestively rubbing the pad of his thumb against the stretched rim of Sideswipe’s valve. His energy field flared with fear, yet Sideswipe practically purred inside Sunstreaker’s head, enthusiasm lighting up their link. “…then I will.”

                “No! I’ll be good, I promise I’ll be good. Please don’t do that, sir! Please!” Sideswipe cried, ruining the illusion a little when he shoved back against Sunstreaker’s fingers. His valve rippled eagerly, calipers cycling restlessly in search of more stimulation. Well, Sunstreaker was about to give him some.

                “Shut up! I’m tired of hearing you babble! In fact… I’d much rather hear you scream. And I have just the thing to make you cry for me. So be quiet while I get your present ready,” Sunstreaker growled, yanking his fingers out to slap Sideswipe’s aft again. Lubricant spattered up in an arc from the impact of Sunstreaker’s soaked digits against equally wet plating.

                “Yes, sir, no sir, I’ll be quiet, sir,” Sideswipe murmured, vents hiccupping. His frame undulated in one long sinuous wave, and Sunstreaker’s mouth went dry as his brother stretched kinking cables.

                _Don’t forget to use the gloves_ , Sideswipe reminded him, startling Sunstreaker out of his reverie. He hastily reached behind him and picked up the waiting bottle and other supplies.

                _I’m putting them on right now,_ Sunstreaker replied, sliding the pair on quickly.

                _Hurry,_ Sideswipe suggested, body shifting sensuously again, the overhead light catching on the trail of fluids seeping down the back of his thighs.

                Sunstreaker fumbled the spike sheath at the sight, nearly dropping the transparent thin rubber. At the last minute, he managed to catch it and finished rolling it onto his aching spike, securing the edges beneath the ring so that the sheath wouldn’t roll off mid-thrust. He definitely did not want that.

                The lubricant Sideswipe had referred to was a failed experiment on Perceptor’s part; the goal had been a soothing nanite gel with numbing properties for the MedBay. What the scientist had accidentally created however, was almost the exact opposite. The pale green substance elicited the sensation of a mild thermal burn.

                How and when Sideswipe had translated that into a pleasurable sensation for himself, Sunstreaker would never know.

                Sunstreaker carefully squirted a small dollop of the ointment onto a rag which he then used to wipe onto the head of his spike. He probably could have used his hand directly, but he didn’t want to accidentally transfer any of the gel to Sideswipe’s frame.

                “This may hurt a little,” Sunstreaker said idly, shuffling forward on his knees and lining his spike up with Sideswipe’s valve. He gripped Sideswipe’s waist, thumb stroking the edge of a transformation seam.

                Sideswipe whined, hips hunching forward away from Sunstreaker’s steadying hand. “Please, sir… don’t…”

                “No backtalk!” Sunstreaker snarled, hilting himself with one smooth motion.

                Sideswipe yelped and his hands flexed, fingers crooking in protest at the rough penetration. When Sunstreaker remained quiescent inside him, Sideswipe gradually began to relax.

                “Sir?” Sideswipe questioned after about a minute of silence and motionlessness on Sunstreaker’s part.

                “It should be kicking in soon,” Sunstreaker promised, sliding a hand around Sideswipe’s waist and capturing Sideswipe’s bobbing spike. He roughly squeezed the hot length making Sideswipe buck backwards, further impaling himself on Sunstreaker’s spike.

                “Oh!” Sideswipe suddenly exclaimed, freezing in place. “That’s… what… what did you do…?”

                _Oh, frag. Sunny… Oh, that feels so good…_ Sideswipe moaned.

                Sunstreaker drew back slightly and then slid forward again, circling his hips to paint the gel over the interior of the depths of Sideswipe’s valve. When he thought he had spread the substance around enough he slowly began fragging his brother, falling into the same steady rhythm he had used earlier to push Sideswipe into his second overload.

                Sideswipe suddenly squealed, jolting in place. Sunstreaker paused, mid-way through withdrawing.

                _Are you ok?_

                “Burns! It burns!” Sideswipe cried, suddenly thrashing against his bonds. “Please, sir, please stop!”

                _Sides?_ Sunstreaker questioned uncertainly. _Sideswipe? Do you really want me to stop?_

                _Ahh, Primus. It really_ does _burn. It was just a warm tingle at first and now…_ Sideswipe finally replied after a worrisome pause. _Primus. I don’t… frag, it’s just… it’s a lot._

                Sideswipe abruptly collapsed, letting the chains support his weight. When Sunstreaker reached forward to turn his twin’s head so Sunstreaker could see his face, he saw that Sideswipe’s faceplates were creased in honest pain.

                _I can stop if you want,_ Sunstreaker offered again, now truly worried. Well, he could withdraw completely and then drag his brother to the washrack to rinse out his valve. There wasn’t exactly an antidote.

                _No. No, don’t stop. It was just a bit of a shock at first; I’m getting used to it. I can take it_ , Sideswipe said after a moment, his voice firming. _Keep talking to me? And frag me, take my mind off it._

                “Well, look at you. You’re doing a lot better than I thought you would,” Sunstreaker purred, stroking Sideswipe’s cheek once before releasing him. Sideswipe turned his head forward again, letting it drop and be supported by the collar as he trembled.

                “Thank you, sir. Thank you! You’re so go- _ood_ to me,” Sideswipe grunted as Sunstreaker began thrusting again. He whimpered piteously once Sunstreaker began moving faster, but Sideswipe’s hips were now meeting Sunstreaker’s, circling backwards in minute little motions.

                “I’m still not hearing you scream, though,” Sunstreaker commented, squeezing Sideswipe’s spike again. The channel surrounding Sunstreaker clenched down in reaction, more lubricant seeping out around the edges. He didn’t know if it was a protective measure done by Sideswipe’s valve or that this was simply that exciting, but it made each glide of his spike almost frictionless.

                “Uh! Frag, yes! Please!” Sideswipe shouted, the words sounding strained as they emerged from his compressed vocalizer.

                “Oh? You like this all of a sudden now?” Sunstreaker asked, awkwardly hunching forward in order to reach around and circle Sideswipe’s anterior node with one finger.

                “I don’t… no?” Sideswipe responded after a beat. “No. You’re hurting me!”

                “Mmm. Your equipment is telling me something differently,” Sunstreaker said, thumbing the head of Sideswipe’s spike and making his pelvis twitch forward. “I think you like it when I put you in your place.”

                _Oh my Primus, Sunny, this is so good. This is perfect, you’re so good to me for real_ , Sideswipe sent in a babbled rush.

                “I don’t! You’re mean and I hate you!”

                _I love you. You’re gonna make me overload so hard, I can’t even…_

                Sideswipe moaned again, head rising up and finally loosening the collar’s grip. A hard tremor ran through him, his fingers clenching uselessly into the air. His valve calipers cycled restlessly, trying to suck Sunstreaker’s spike deeper.

                “Nnghh… please… please, sir,” Sideswipe groaned as Sunstreaker’s pace began to quicken.

                “Please? Please _what_ , you useless little glitch?” Sunstreaker murmured, leaning forward and nipping at Sideswipe’s back.

                Sideswipe whined deep in the back of his intake, shoving back against Sunstreaker’s spike more violently. “Oh, Primus. Oh, _Primus_ , please! Let me overload!”

                _How do you want it?_ Sunstreaker asked, squeezing Sideswipe’s spike again.

                All he got back in reply was an unintelligible blurt of static, Sideswipe’s end of their bond beginning to narrow just as it had earlier. Sideswipe had warned him ahead of time he would be doing this, citing it wasn’t fair to drag Sunstreaker through an overload his own body couldn’t complete because of the spike ring.

                So Sideswipe was close then. Not that Sunstreaker couldn’t tell what with all the other signals his brother’s body was giving off. Sideswipe’s poor cooling fans were whining with how fast they were going and his plating was flared so wide Sunstreaker could practically see through him.

                “Never said you couldn’t. Might as well get a show out of my efforts. Go on then. Impress me.”

                Sunstreaker got a good hold of Sideswipe’s hips and began thrusting forcefully, his aft and Sunstreaker’s pelvis meeting in a lewd squelch every time he bottomed out. He couldn’t wait for Sideswipe to climax; once he had his third, it was Sunstreaker’s turn. And although he’d been through overload denial before, it was never easy to bear, especially with his brother enjoying his so enthusiastically.

                Although, Sideswipe wasn’t quite tipping over the edge as easily as he had for his first two overloads. He was whining desperately, frame rigid except for the small shivers which ran through him every few seconds.

                Sunstreaker suspected it was due to the nanite gel. It was probably still causing conflicting signals to the sensors inside Sideswipe’s valve, no matter how much he enjoyed a little pain mixed into things.

                “Useless little thing. Look at you. All that I’ve done for you and you won’t even overload when I tell you to,” Sunstreaker growled, holding Sideswipe’s hips still as he ground against his aft in a small circling motion before withdrawing and starting back into that steady rhythm.

                “I’m sorry!” Sideswipe choked out. “You’re… you’re right… I’m useless, I’m… I’m… unh, please! Please, Sir! Help me!”

                Sunstreaker considered the arched back of his brother for a moment, before stilling and reaching over to his side.

                “No, no, no, don’t stop!” Sideswipe protested shrilly, his shoulders creaking as he strained backwards as far as the chains would let him, hips circling fitfully and stirring Sunstreaker’s spike within Sideswipe’s port.

                “Calm down,” Sunstreaker chided, slapping Sideswipe’s aft hard enough to leave a scrape of yellow paint behind. “I’m getting you another present.”

                “… another… another present?” Sideswipe asked faintly, engine revving at an increasingly higher pitch. He was likely to blow more than a few circuits at this rate, something Ratchet would definitely not appreciate. Sunstreaker needed his brother to climax and fast.

                “You’ll like this,” Sunstreaker said confidently. Way more confidently than he felt, to be honest. He gripped Sideswipe’s spike in a nanite gel covered hand and stroked several times, coating the length completely before reaching farther back and circling Sideswipe’s engorged nub with more of the same substance.

                Once both were amply coated, he thrust as deeply as he could into Sideswipe’s valve, grinding hard enough against Sideswipe’s aft that his brother’s thighs started trembling in the effort to hold himself up. Sunstreaker circled his pelvis over and over again, doing his best to stimulate that deep, recessed ceiling node. At the same time, he took hold of Sideswipe’s spike in a punishing grip and began roughly stroking it.

                Sideswipe gasped, hips eagerly getting into the rhythm Sunstreaker set with his hand. A few moments later, however, he shuddered and then froze.

                “Sir? What… what...?” he asked, voice shaking and cracking.

                “You seemed to like that gel so much…” Sunstreaker’s hand faltered, uncertain.

                “Oh… ohhhh… you…” Sideswipe moaned, his plating ruffling in random little waves. “Sunny… keep going… don’t stop. Even if I die.”

                Sunstreaker chuckled in relief, his hand resuming its stroking. If Sideswipe could joke about things, he was fine. Although that was the first time he had broken character…

                “You’re not going to…”

                All of a sudden, Sideswipe threw his head back with a shriek, the sound of plating tearing apart echoing in Sunstreaker’s audials. The collar, he realized, with a sick lurch to his tanks.

                _Don’tstopdon’tstopdon’tstop_ , Sideswipe began chanting, still screaming loud enough to wake the dead. _Harder… I’m fine, promise… just… keep hurting me…_

                Sideswipe started thrashing in his bonds, the thin chain attached to his collar suddenly snapping. The ceiling above them creaked ominously, and Sunstreaker gave it a startled glance before returning his attention to the wildly undulating frame under him. Sideswipe’s valve was rippling, calipers clenching down so hard Sunstreaker couldn’t have withdrawn even if he wanted to. As it was, he just continued to jerk off Sideswipe’s spike, feeling it swell between his fingers.

                Just as Sideswipe’s howl reached Starscream levels, Sunstreaker leaned forward and sank his denta into red plating, directly below Sideswipe’s sensitively edged windshield.

                The scream abruptly cut off, Sideswipe’s spike erupting transfluid onto the floor. His frame locked up, head thrown back. A painful sounding grunt heralded a series of little jerks of his hips, several more spurts of transfluid dribbling up over Sunstreaker’s fingers.

                The faintest hint of energon coated his glossa as he released Sideswipe’s back. He kissed around the dented and torn plating, pulsing out his energy field in a soothing manner, as Sideswipe’s spike twitched weakly one last time and began to soften.

                “You’re all right, I got you,” he murmured into his brother’s armor. “That was beautiful, quite the show.”

                Sideswipe’s head lolled to the side, resting against his inner upper arm. His ventilations started back up again, Sunstreaker not even realizing they had stalled until he both felt and heard the rapid motions. His own core temperature readings were beginning to climb, affected by the sheer amount of heat put off by his brother’s frame.  

                Little by little, tension cables in Sideswipe’s body began to relax. The calipers of his valve twitched a few more times before releasing their hold on Sunstreaker’s spike. It slipped out as Sideswipe sagged forward, the entirety of his weight now supported by his wrists.

                _Hey. Doing ok_? Sunstreaker asked, nudging along their bond. Sideswipe’s mental walls were easily pushed aside, and Sunstreaker momentarily floated along with his brother in a sea of deep satisfaction. Sideswipe didn’t reply with words, only a lazy swell of gratitude and fulfillment.

                “I have one more present to give you,” Sunstreaker informed his twin, shuffling backwards until he had enough room to stand. He carefully rolled both the gloves and spike sheath off and tossed them to the side. Surprisingly, there wasn’t a drop of the nanite gel on him, although splatters of regular lubricant were splashed against his pelvic span.

                “Mmm?” Sideswipe hummed, stirring. His optics shutters opened a crack as Sunstreaker moved around to stand in front of him.

                “Settle on your knees,” Sunstreaker instructed. He took ahold of Sideswipe’s wrists and pulled him up enough to unhook the cuffs from the dangling chain. Sliding his hands down Sideswipe’s arms, he gently propelled him backwards. Even with the assistance, Sideswipe wobbled badly. Yet he managed to rock himself backwards with one large heave. He ended up with his aft resting on the heels of his pedes, his arms dropping to lie limply in his lap. Sunstreaker left them cuffed; he could get to that and the ties around Sideswipe’s legs later.

                “Another present, sir?” Sideswipe murmured, blinking slowly in an otherwise slack expression.

                Sunstreaker took a step forward, the inside of his pedes nudging the outside of his twin’s knees. As he flicked the switch to the spike ring, deactivating it, he reached forward and traced Sideswipe’s plump bottom lipplate. The soft dermal covering was swollen, deep indentations present in one side from where Sideswipe had worried at it with his denta.

                “Open your mouth,” Sunstreaker said softly, sliding the overload inhibitor off with a relieved sigh. Sideswipe wasn’t the only one running hot. But now that his brother had been taken care of, Sunstreaker could focus a little more on his own needs.

                “Who do you belong to?”

                Sideswipe shivered as his jaw dropped obediently. “You, sir.”

                Sunstreaker began stroking his spike in earnest, the charge practically crackling against his fingertips. “That’s right,” he panted, knowing he wouldn’t last more than a few moments. Not with his brother kneeling there on the floor, utterly debauched, the pool of lubricant spreading wider as it dripped steadily out of his bared array. “You’re mine.”

                “Every inch of me, sir,” Sideswipe promised, optics reverently trained on Sunstreaker’s face.

                _Overload for me, Sunstreaker. All over my face. I want it dripping down my cheeks,_ Sideswipe encouraged.

                “Oh, frag,” Sunstreaker moaned loudly, his hips thrusting forward. He was helpless to the powerful overload that abruptly rose up and washed over him, making support cables in his abdomen and lower back seize and release in little spasms. Spike jerking in his hand, he did exactly as Sideswipe had commanded, aiming at his twin’s eagerly extended glossa.

                His optics fritzed and offlined despite Sunstreaker’s best efforts. As all the tension in his body left, departing through his spike, he fought to reboot his visual centers. A moment later, he was successful, and he onlined them to see that his aim had been true. Spatters of transfluid were dripping down Sideswipe’s cheeks and nasal ridge, his glossa repeatedly darting out to lick at the drops. Their optics met, Sunstreaker marveling at the blissed out expression Sideswipe was sporting.

                “Thank you, sir. You’re so good to me, sir,” Sideswipe murmured, bound hands rising up to clasp Sunstreaker’s thigh.

                “You’re welcome,” Sunstreaker replied, abruptly feeling weak in the knees, the dissipating charge leaving him tingly, tired, and very much aware of everything he’d done over the past hour. His processor swam, rapidly gathering up all the input he had shoved aside earlier to analyze later. Well, it was later now.

                Sideswipe’s grip firmed. “Session’s over. Unlock these?” he asked, raising his hands up higher. Sunstreaker automatically reached for the cuffs, finally managing to open them after several tries. For some reason, his hands wouldn’t stop shaking.

                As soon as Sideswipe’s hands were free, he reached behind him and quickly released the spreader. Sunstreaker watched him struggle to stand, absently thinking he should offer a hand, but unable to follow through on the thought. Instead, he just swayed in place, blinking down at his brother.

                Sideswipe finally made it to his feet and placed a hand on Sunstreaker’s lower back. Making soothing little chirps, he gently pushed Sunstreaker towards their berth. A rag was pulled from Sideswipe’s subspace and he wiped his face as they moved, a little to Sunstreaker’s disappointment.

                Sunstreaker let himself be propelled, and then nudged down onto the bed, the protective liner crinkling as his weight settled atop it. Sideswipe climbed up next to him and pulled the waiting blanket up over both of their frames.

                “C’mere,” Sideswipe murmured, tugging Sunstreaker into his arms. “That’s it. There you go. That was amazing, Sunny. You did so good, I’m really proud of you.”

                He only realized how badly he was shivering when their amour began to rattle together loudly. As he tried to pinpoint when that had started, his gaze lowered and focused in on the drying energon on Sideswipe’s chest. Sunstreaker made a tiny little whimpering sound in the back of his intake.

                “Oh, hey, hey. No, it’s ok,” Sideswipe said hurriedly, grasping Sunstreaker’s jaw and tilting his face up so that their optics met. Sideswipe’s energy field swelled, encompassing both of them in contentment and reassurance.

                “I hurt you.”

                He should have pulled Sideswipe to his feet and wiped him down. The gel’s intensity wore off pretty quickly but the feeling of a minor burn would persist for several hours. Sideswipe needed to have the stuff washed off and out of him.

                “I asked you to. And I loved every minute of it,” Sideswipe reassured him. Gentle hands stroked his cheek and his shoulder and Sunstreaker relaxed into the familiar touches. Well… Sideswipe didn’t seem to mind the lingering lubricant…

                “Really?” He didn’t know why he even asked. That expression on Sideswipe’s face as Sunstreaker had overloaded all over him was answer enough. But yet, he still needed to hear it directly from his twin’s mouth.

                “Absolutely. That last overload…” Sideswipe shuddered, his optic shutters squeezing shut in remembrance. “Primus… that was amazing.”

                “Did I do everything right? Did I say the right things?” Sunstreaker asked, tensing in sudden worry.

                Sideswipe gently pressed Sunstreaker onto his back and then clambered atop him once he was prone. His aft settled onto Sunstreaker’s knees, Sideswipe’s own pressing against Sunstreaker’s sides. His brother crossed his arms across Sunstreaker’s chest and looked down at him intently.

                “You did and said everything just like I asked you to. I couldn’t be happier. Was there anything you would you do differently?” Sideswipe inquired.

                Being trapped beneath Sideswipe’s weight did wonders in calming Sunstreaker’s anxiety, especially when Sideswipe gathered up Sunstreaker’s hands and placed them between their chests, flattening Sunstreaker’s palms to his own chestplate.

                “I… I don’t know…” Sunstreaker replied. “I just…” His optics caught on the trail of drying energon on Sideswipe’s throat. The band of metal still rested there. “I hate that collar.”

                “This?” Sideswipe reared up, immediately unfastening the thing and then tossed it over the side of the bed. “Gone. Won’t use it anymore,” he promised. “What else?”

                With the collar gone, Sunstreaker could see the multiple rips and holes ringing Sideswipe’s neck, some still seeping. He didn’t seem to be in the least bit bothered by the wounds; then again, they both had sustained far worse in battle.

                Sunstreaker mutely shook his head, raising his helm to press a kiss against Sideswipe’s lips. Sideswipe’s hummed against Sunstreaker’s mouth, hands reaching up to gently finger his helm slats. The touch soothed Sunstreaker and he allowed the kiss to end, head falling back down to the pillow beneath it.

                “I should clean you up,” he murmured, thinking again about the gel trapped behind Sideswipe’s panels.

                “Later,” Sideswipe replied. “I’m fine. I’m more concerned about you right now. I asked a lot of you, I know that. This isn’t in your nature.”

                Sunstreaker canted his optics off to the side. “I’ve been rough with you before,” he whispered, a little ashamed of the fact. The more sessions they had together, the more he realized exactly _how_ rough he had been in the past. There was no excuse for it, although fortunately Sideswipe had always been willing. Maybe that was why Sunstreaker was still a little shook up. Sideswipe had played the unwilling victim a little _too_ well.

                Sideswipe tilted his head to the side, considering him. “Yeah. But I haven’t minded. I didn’t today, either. Except it was hard to remember that, wasn’t it?”

                He always did that. Sideswipe always saw right through him.

                Sunstreaker nodded. “It made me feel…” he trailed off, unable to put the feeling into words. Despite Sideswipe being the one who had been chained and helpless, he had undoubtedly still been the top throughout the entire session. It had felt right to follow his orders, but wrong to put him through that, to act as if Sunstreaker were...

                Sunstreaker shunted that thought aside. Consent was a tricky thing; Sideswipe himself knew that.

                Continuing to pet Sunstreaker’s helm, Sideswipe slowly nodded. “Maybe I pushed for too much, too fast. I probably should have started with just the position and the chains. I think I got too greedy.”

               “I thought I could handle it,” Sunstreaker admitted. They had discussed every aspect of the session in great detail ahead of time, Sideswipe planning everything out as meticulously as always. The only deviation had been Sunstreaker slathering the gel further across Sideswipe’s array. “I should have been able to handle it.”

               “There is no ‘should have’. Sunny, if you felt uncomfortable, you could have used the safe word. I have to be able to trust you to do that,” Sideswipe chided, his gaze darkening in intensity. “That’s why I asked you to unmask your energy field; I couldn’t see you properly so I was relying on that and the bond for me to monitor you. I thought I had a good measure of your state of mind, but I obviously got a little distracted. That’s what I get for trying to both be a guinea pig for pain in your sessions and subbing at the same time.”

               Sunstreaker shook his head again. He hadn’t thought he had been projecting distress. Maybe a little uncertainty here and there, but nothing informative enough for Sideswipe to pick up. “I think you were reading me fine. It’s just… then and now… when it all sinks in…”

               Sideswipe nodded sagely. “Ah. I know what that’s like. This was a really tricky scenario, I know that. I still think you did great though.”

               “I… I want to do it again sometime,” Sunstreaker said slowly, trying to gather his feelings and thoughts about the matter. “It’s not fair for you to always be… you need… I want to help…”

               “Shhhh, it’s ok. Trust me, bro, I get a lot out of me topping you. I wouldn’t keep doing it if I didn’t. This was just an added bonus. I’d love it if you were comfortable enough to dominate me again, maybe even without me talking you through it in real time. But I’m not going to pressure you; if you’re not comfortable, that’s ok.”

               “You always say I should push my comfort level,” Sunstreaker muttered, a bolt of fear going through him at the thought of topping his brother without help. He wouldn’t have the slightest idea what to do, especially since what Sideswipe was looking for was completely different than what Sunstreaker needed.

               “Slowly. Carefully,” Sideswipe replied with a small grin. “I can wait. And patiently too, believe it or not.”

               Sunstreaker knew Sideswipe had patience to spare. At least in the berthroom; on the battlefield, that was another matter. Yet, it still sat ill with Sunstreaker that he couldn’t do for his twin what Sideswipe did for him on a routine basis. He wanted to see that blissed expression on Sideswipe’s face more frequently. Sunstreaker knew how freeing it could be to just let go and be taken care of by someone else.

               “What else bothered you?” Sideswipe inquired, giving him a shrewd look.

               Sunstreaker settled a little more comfortably onto the berth, considering. It had been incredibly rewarding to please his twin, to follow his orders. But Sunstreaker hadn’t quite reached that quiet place in his head that he normally descended into during a session. He had been too worried about getting things right, and while Sideswipe had supported him the entire way and was even taking care of him now, Sunstreaker hadn’t received his twin’s full focus and care for the entire scene.

              He supposed that made him selfish. But he had come to expect that attention and devotion and he felt a little off balance that he hadn’t received it. Even knowing full well ahead of time that that would be the case.

              “I… you…” Sunstreaker started and then trailed off, uncertain how to word it.

              “Still feel a little unsatisfied?” Sideswipe supplied. Sunstreaker threw a startled glance at his brother. Sometimes it surprised even him how well Sideswipe knew him. Of course, Sideswipe was way off the mark occasionally, but other times it was like Sideswipe lived in Sunstreaker’s very processor.

              “Kind of?” Sunstreaker replied, cringing a little. “Do you ever…?”

              Sideswipe’s knees tightened against Sunstreaker’s waist. “No, Sunny. I always feel great after our sessions. Look, you’re not a top. I can walk you through the motions and coach you on what to say, but it likely won’t ever come naturally to you. That was my one hesitation about today; I didn’t know if you would hit your proper headspace. And I’m pretty sure you didn’t, am I right?”

              “No. I mean, yes, you’re right. I came close. Following orders… making you overload… but it was… you were facing away from me…”

              But that wasn’t it either. Sideswipe had used sensory deprivation on him before, essentially blinding him. What was it exactly that had made Sunstreaker feel so off balance about it all?

              “Shhh…” Sideswipe murmured, rocking atop him and regaining Sunstreaker’s attention. He realized he had tensed, ventilations quickening. He forced himself to relax, to feel the way Sideswipe had caged him in in a protective cocoon.

              “It’s a combination of a lot of things, Sunny. I’ve ordered you to please me before, but never like this. Not while I’ve been turned away from you. You feed off my expressions; you constantly look up at me while you’re eating me out or sucking me off. It’s super hot,” Sideswipe confessed, leaning forward to affectionately brush his nasal ridge against Sunstreaker’s cheek.  

              “I was telling you to stop and even though you knew it was an act, your instinct in a session is to obey. Then there was the fact that we were using the bond, something we’ve never done before, so another thing for you to adjust to, especially as a way to receive instructions. And then you didn’t have the visual cues of my expressions. So yeah, I’m not surprised things didn’t quite sit right with you,” Sideswipe summed up, once again perfectly nailing it on the head.

              Except for one thing.

              “You’ve also never told me to hurt you before,” Sunstreaker added. And even knowing Sideswipe had needed that, enjoyed that, it was still a little distressing to do so.

              Sideswipe looked thoughtful. “Mmm. And if you have, I’ve punished you for it. Poor baby. Your head’s a mess right now, isn’t it? I’m sorry. I’ve got some thinking to do before we try this again,” Sideswipe mused, optics going distant. Sunstreaker had no doubt that Sideswipe’s odd little processor was already calculating out new scenarios and interactions.

               Sunstreaker suddenly drew his knees up, forcing his brother to slide forward a little, a surprised ‘meep’ sound emerging from his throat.

               “Think later,” Sunstreaker instructed. He wanted his brother with him entirely in this moment.

                Huh. He _was_ selfish; he didn’t even like sharing Sideswipe with Sideswipe.  

                Sideswipe’s optics glinted with amusement as he resettled, this time with his mouth hovering mere inches above Sunstreaker’s. Tease.

                “Demanding little sub, aren’t you?” he remarked, lips curling up at one corner in a lopsided smirk.

                “Maybe. And I demand that you pay attention to me,” Sunstreaker instructed, only half joking. He didn’t like feeling like this. He wanted… no, he _needed_ Sideswipe to fix it.

                Sideswipe’s hips moved in a slow figure eight, painting his still warm interface panel across Sunstreaker’s in a sensual slide.

                “You sure that’s what you want?” he asked. His energy field smoothed out around the edges, his shoulders dropping subtly in a familiar way that made Sunstreaker’s spark beat excitedly, desperately.

                Sunstreaker gave a little nod, struck speechless at the way Sideswipe arched himself into a seated position, the blanket falling from his shoulders to pool around their waists. His hand trailed suggestively down his chest to circle his right headlight.

                “What if I deny you things? An overload, maybe? What if I work you over, bring you to the edge again and again, make you beg me to end it? And then just walk away?” Sideswipe inquired with a challenging arch to one orbital ridge.

                Sunstreaker’s hands flexed against his brother’s thighs, fingers briefly digging into the lateral seam before smoothing over the edges. “As long as you don’t actually leave me,” he replied, voice cracking.

                Sideswipe suddenly swooped downward, supporting his weight on palms placed to either side of Sunstreaker’s helm. Warm ex-vents bathed Sunstreaker’s parted lips for a long moment, his ventilations catching in suspense. Then,

                “Deal.”

 

~ End     

 


End file.
